The idea is that all enemies must die all together at the same ONE second.
Thoretiaclly, you set things so that there are two groups of crowded nerds stay still in different locations, not so far away, so that you can see them and reach them from the place you're at. You throw the greande towards the first group. Meanwhile the grenade reaching the destination, you shoot rocket in the direction of another group of nerds. If you calculate all so that both whizbangs reach the target simultaneously and everyone has 1hp, how many nerds can you defeat in a split of second?